It is an all too often occurrence in my line of work as a hospital pharmacist that I see patients coming into the Emergency Room doubled over with abdominal pain. This isn’t your typical upset-stomach-because-you-ate-something-spicy kind of pain, but rather a severe give-me-morphine-now type pain. The pain is obviously bad enough to land someone in their local ER. Otherwise, they’d just pop some Tums and call it a night.

What’s happening here? Why are these patients in so much pain?

While many different medical conditions can cause abdominal pain, diverticulitis is one of the common culprits in cases like the one described.

What Is Diverticular Disease?

Diverticulitis is a condition contained in a broader range of conditions known as diverticular disease. Diverticulosis is the other condition in this group. I’ve provided the definitions of the two terms below to distinguish between them:^[1]

Diverticulosis – The presence of one or several small, sac-like outpouchings, called diverticula, protruding from the colonic wall. (To picture this, imagine a long, slender, inflated balloon, much like the balloons used to make balloon animals. If you squeeze this inflated balloon just enough you can make a little bubble protrude out of its side. The formation of this “bubble” would be very similar to the diverticula formed in the wall of your large intestine. These diverticula are like little tiny pouches sticking out of the side of your colon.)

Diverticulitis – The acute inflammation of diverticula associated with fever, pain, and possible infections.

Diverticulosis occurs first. This condition usually flies under the radar though because most people never know they have it unless it’s found on a routine colonoscopy. Diverticulitis comes after, and it’s the reason people end up in the ER with pain. Ten to twenty-five percent of affected individuals with diverticular disease will develop symptoms in the form of abdominal pain, bloating, irregular bowel movements, bleeding, or signs of infection.^[2][3]

Diverticular disease is common in industrialized nations, affecting up to 60% of the population over age 60.^[3] In fact, some of the first researchers to study the medical condition labeled it a “20th century problem” and “disease of Western civilization.”^[2] The United States and Europe have the highest rates of diverticular disease in the world, while it is rarely found in developing countries.^[3][4]

What Causes Diverticular Disease & How Does It Develop?

If you read the research, all the studies agree on one thing—the cause of diverticular disease isn’t completely known, but a low-fiber diet most likely plays a significant role.^[1-5] Based on the high prevalence of this condition in Western countries, and the rare occurrence in developing countries, this makes sense. For one, Western cultures eat a diet high in animal-based and processed foods. Animal foods are completely devoid of fiber. You won’t find any in meat, dairy, or eggs. Processed foods are also fiber poor. Most of their fiber is stripped out during the manufacturing process.

In contrast to Western civilization, populations of developing countries (those found in many parts of Africa, Asia, and parts of South America) often eat a traditional diet of mostly unrefined plant foods with only small amounts of animal-based and processed foods. Unrefined plant foods are full of fiber and aid in the prevention of many chronic diseases.

So what does fiber have to do with any of this?

The answer is plenty. Fiber is essential to the formation of healthy bowel movements. Without it, or with very little of it, constipation can become a chronic problem leading to hard, compact stools requiring excessive straining to force out of the bowel. (To learn more about constipation, read my article, ”The Anatomy of a Bowel Movement (And How to Cure Constipation).”)

Over time, this constant straining puts pressure on the inside walls of the colon (i.e. large intestine).^[6][7] The increase in pressure results in the formation of the small, sac-like outpouchings (diverticula) we talked about earlier. These diverticula “bubbles” form at points of weakness in the intestinal wall. Most diverticula are actually very small—on the order of only a centimeter or two—but, nonetheless, are still big enough to cause symptoms and complications in some people.^[8]

The inflammation, pain, and infections that develop with diverticular disease are a result of a series of events. Constipation leads to stagnant fecal matter that finds itself sitting in the diverticula pouches.^[4] Basically, your poop is “stuck” in the “bubbles.” This in turn triggers inflammation of the intestinal wall. Pain, fever, bleeding, abscess formation (pus-filled sacs), and other complications can occur.

In addition, the balance of the gut bacteria can also be altered due to chronic constipation and a low-fiber diet. Instead of a colon full of “good” (healthy) bacteria, there is an increase in “bad” (infectious) bacteria that populate the colon. This can further increase the chances of an infection developing.

Treatment Options for Diverticular Disease

The best treatment for diverticular disease is prevention, but if you do happen to develop the condition there are a number of options to look at—the most important being a lifelong high-fiber diet consisting of unrefined, whole plant foods.

Treating Acute Diverticulitis

Acute attacks of diverticulitis will often require bowel rest and possible medical intervention (antibiotics, workup, drainage of abscesses, surgery, etc.) depending on the severity. The good news is approximately 75% of patients will experience pain without inflammation, and of these only 1-2% will require hospitalization and 0.5% will require surgery.^[4]

Most patients can be put on bowel rest, which involves abstaining from all solid foods for 2-3 days before gradually returning to a regular diet (high in fiber of course). During this time a clear liquid diet (water or other clear beverages) must be started and adhered to.

An absolute must in treating acute diverticulitis is a high-fiber diet if patients wish to prevent complications and recurrences of disease.

Antibiotic therapy has been the standard of care for years to eradicate any infection occurring with diverticulitis and is often prescribed preemptively even if no infection is present. However, recent studies have shown that antibiotic treatment was not necessary or did not accelerate recovery or prevent future complications/recurrences of acute uncomplicated diverticulitis in patients.^[9][10] It’s important to note that both studies referenced here say that further studies are needed to determine definitive antibiotic treatment in acute diverticulitis.

With that being said, if you find yourself in your doctor’s office or local ER suffering from an acute attack of diverticulitis, you are likely to be prescribed an antibiotic to ward off any possible infection. This is a reasonable step in my opinion given the alternative—a potentially untreated, small infection that could develop into a large-scale, serious infection requiring hospitalization. I will be the first to admit that infectious disease is one of the areas in modern medicine that we excel in and should be used when the situation calls for it.

Finally, an absolute must in treating acute diverticulitis is a high-fiber diet if patients wish to prevent complications and recurrences of disease. It should be started as soon as the patient can tolerate solid foods again, after their initial bowel rest.

Treating & Preventing Diverticular Disease

Patients who experience an acute attack of uncomplicated diverticulitis may have chronic recurrences of the disease. A 2010 study in the British Journal of Surgery followed several hundred patients with uncomplicated diverticulitis for up to ten years and found that 18.8% had one recurrent episode and 4.7% had two or more recurrences of the disease.^[11]

The goal for any patient with diverticular disease is to not to have any recurrences of disease. So what’s the best way to accomplish this?

Fiber. Once again, a high-fiber diet is essential to preventing any recurrent attacks of diverticular disease. The cause of the disease, as you now know, is a low-fiber diet. There is a plethora of evidence showing this.

The Health Professionals Follow-Up Study looked at fiber and food intake and the risk of developing diverticular disease in 51,529 male health professionals.^[2] The information gathered from this trial is invaluable. In general, risk of diverticular disease went down as fruit and vegetable consumption went up. Beef, lamb, pork, processed meats, cookies, potato/corn chips, French fries, and white bread were all associated with an increase in diverticular disease. As an interesting side note in this study, physical activity (running/jogging) was also shown to reduce the incidence of diverticular disease.

The above data mirrors a 6-year follow up study of 690,075 women in the UK where researchers found that as fiber intake increased, the risk of diverticular disease decreased.^[5] The strongest correlation of disease reduction was with fruit and cereal fiber consumption. Vegetable fiber also reduced disease risk.

Risk of diverticular disease went down as fruit and vegetable consumption went up.

Another study evaluated the effects of implementing a high-fiber diet in one hundred patients diagnosed with acute diverticulitis.^[3] After 5-7 years on a high-fiber diet 91% of the patients remained symptom-free.

Four highly respected professional health organizations responsible for formulating official guidelines for the prevention and treatment of diverticular disease also agree with the evidence-based literature on increasing fiber intake in preventing and treating diverticular disease. They include:^[3]

• American College of Gastroenterology
• European Association for Endoscopic Surgery
• American Society of Colon and Rectal Surgeons
• World Gastroenterology Organization

This speaks volumes to the importance of adopting dietary changes to prevent or treat this medical condition. As you know from reading many of my previous articles, modern medicine is not always the quickest to embrace safe, conservative, and highly-effective dietary treatment options for the majority of our chronic diseases in the Western world. I commend and applaud the above organizations for their recommendations in treating this illness using diet as a first-line agent.

One more thing I’d like to point out with traditional medical advice regarding diet and diverticular disease is the notion that persons need to avoid nuts, seeds, corn, and popcorn. Two studies have refuted this unfounded claim in recent years.^[8][12] A 2009 article in Clinics in Colon and Rectal Surgery states, “Without any good evidence, certain foodstuffs such as nuts, seeds, popcorn, and corn have long been implicated in the development of diverticulitis and are often advised against by physicians. They were thought to provoke diverticulitis or diverticular bleeding by causing luminal trauma. In a large prospective study of men without known diverticular disease, State et al found that nuts, corn, and popcorn consumption did not increase the risk of diverticulosis, diverticulitis, or diverticular bleeding.”

Medication Used in Treatment of Chronic Diverticular Disease

A small number of medications may be used in treating chronic cases of diverticular disease including anti-inflammatory drugs, antispasmodic drugs, and antibiotics. I am only going to briefly discuss one—the antibiotic Rifaximin.

Rifaximin is an antibiotic currently being used in chronic diverticular disease. It is poorly absorbed into the bloodstream with 97% of the drug being excreted in the feces unchanged.^[13] This means most of it stays in the gut, and, therefore, targets “bad” bacteria that have overgrown the colon. The hope is to reduce symptoms and complications of diverticular disease.

A 2011 meta-analysis reviewed four trials looking at Rifaximin treatment for chronic diverticular disease.^[14] Researchers found after one year of treatment the numbers needed to treat (NNT) for Rifaximin were:

1 of 3 people (33.3%) achieved symptom relief
1 of 9 people (11.1%) avoided further complications of diverticular disease

As with any medication there are possible side effects to consider before taking Rifaximin. The most common side effects include: peripheral edema (15%), nausea (14.3%), dizziness (12.9%), fatigue (12.1%), ascites (11.4%), diarrhea (10.7%), headache (10%), muscle spasms (9.3%), itchiness (9.3%), and abdominal pain (8.6%).^[15]

Summary

Diverticular disease is a common disease in Western cultures. It is a disease of dietary causes, namely low fiber intake. Symptoms and complications can lead those suffering from the condition to seek medical care. Acute attacks of diverticulitis will require bowel rest and may also need antibiotics to fight off infection. Surgery for severe cases is rarely needed.

Your best bet is to avoid diverticular disease in the first place by adopting a high-fiber diet consisting of unrefined, whole plant foods. It bears repeating that animal foods (meat, dairy, and eggs) contain no fiber at all, and processed foods contain very little. These foods should be limited or avoided altogether in order to produce the best possible results in both the prevention and treatment efforts of diverticular disease.

Eat plants. Get lots of fiber. Live happy. And avoid doctors and pharmacists if at all possible by adopting a whole food, plant-based lifestyle. Your body will thank you for many years to come.

References

1. Matrana MR, Margolin DA. Epidemiology and pathophysiology of diverticular disease. Clin Colon Rectal Surg. 2009 Aug;22(3):141-6.
2. Aldoori W, Ryan-Harshman M. Preventing diverticular disease. Review of recent evidence on high-fibre diets. Can Fam Physician. 2002 Oct;48:1632-7.
3. Unlu C. Daniels L, et al. A systemic review of high-fibre dietary therapy in diverticular disease. Int J Colorectal Dis. 2012;27:419-427.
4. Boynton W, Floch M. New strategies for the management of diverticular disease: insights for the clinician. Ther Adv Gastroenterol. 2013;6(3):205-213.
5. Crowe FL, Balkwill A, et al. Source of dietary fibre and diverticular disease incidence: a prospective study of UK women. Gut. 2014;63:1450-1456.
6. Burkitt DP, Walker AR, Painter NS. Effect of dietary fibre on stools and the transit-times, and its role in the causation of disease. Lancet. 1972;2:1408-1412.
7. Painter N, Truelove S, et al. Segmentation and the localization of intraluminal pressure in the human colon, with special reference to the pathogenesis of colonic diverticula. Gastroenterology. 1968;54(Suppl):778-780.
8. Beckham H, Whitlow CB. The Medical and Nonoperative Treatment of Diverticulitis. Clin Colon Rectal Surg. 2009;22:156-160.
9. Chabok A, Pahlman L, et al. Randomized clinical trial of antibiotics in acute uncomplicated diverticulitis. Br J Surg. 2012 Apr;99(4):532-9.
10. Hjern F, Josephson T, et al. Conservative treatment of acute colonic diverticulitis: are antibiotics always mandatory? Scand J Gastroenterol. 2007;42(1):41-47.
11. Eglinton T, Nguyen T, et al. Patterns of recurrence in patients with acute diverticulitis. Br J Surg. 2010 Jun;97(6):952-7.
12. Tarleton S, DiBaise JK. Low-residue diet in diverticular disease: putting an end to a myth. Nutr Clin Pract. 2011 Apr;26(2):137-42.
13. Hong KS, Kim JS. Rifaximin for the treatment of acute infectious diarrhea. Therap Adv Gastroenterol. 2011 Jul;4(4):227-35.
14. Bianchi M, Festa V, et al. Meta-analysis: long-term therapy with rifaximin in the management of uncomplicated diverticular disease. Aliment Pharmacol Ther. 2011;33:902-910.
15. Bass NM, Mullen KD, et al. Rifaximin treatment in hepatic encephalopathy. N Engl J Med. 2010 Mar;362:1071-1081.